Superegenerative radio frequency techniques are well known in the art of radio communication. Systems operating in accordance with superegenerative radio frequency techniques continue to be manufactured in extremely large quantities for serving a variety of short range RF applications. The popularity of such regenerative radio frequency techniques is due primarily to simplicity of design and low manufacturing costs. Examples of superegenerative radio frequency systems may be found in U.S. Pat. No. 3,671,868 (Saunders); U.S. Pat. No. 5,146,613 (Anderson) and U.S. Pat. No. 4,210,898 (Betts).
However, superegenerative radio systems are subject to frequency drift and unrestrained bandwidth problems as a result of environmental changes and the aging of components within the radio circuitry. This often results in undependability of the systems and potentially critical deficiencies within relatively short periods of duty.
A further prior art superegenerative receiver is disclosed in U.S. Pat. No. 5,105,162 (Fleissner et al). In this Patent, a system is provided for automatically tuning the centre operating frequency of the receiver prior to production. In Fleissner et al, a signal generator and spectrum analyzer are used to permanently set the receiver to the desired centre operating frequency.
Thus, Fleissner et al provides an electronically locked tuning frequency as contrasted with prior art mechanically locked systems such as epoxied inductor cores, spring loaded capacitor/resistor barrels, etc. Once the centre operating frequency of the receiver has been permanently set, ageing components and temperature changes in the receiver will eventually result in the well known dependability problems of the prior art superegenerative receivers discussed above.